Use buffer pooling in IOutputFormatters

src/Microsoft.AspNet.Mvc.Abstractions/Formatters/OutputFormatterWriteContext.cs

@@ -2,6 +2,8 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using System.IO;
+using System.Text;
 using Microsoft.AspNet.Http;
 
 namespace Microsoft.AspNet.Mvc.Formatters
@@ -15,16 +17,23 @@ namespace Microsoft.AspNet.Mvc.Formatters
         /// Creates a new <see cref="OutputFormatterWriteContext"/>.
         /// </summary>
         /// <param name="httpContext">The <see cref="Http.HttpContext"/> for the current request.</param>
+        /// <param name="writerFactory">The delegate used to create a <see cref="TextWriter"/> for writing the response.</param>
         /// <param name="objectType">The <see cref="Type"/> of the object to write to the response.</param>
-        /// <param name="@object">The object to write to the response.</param>
+        /// <param name="object">The object to write to the response.</param>
-        public OutputFormatterWriteContext(HttpContext httpContext, Type objectType, object @object)
+        public OutputFormatterWriteContext(HttpContext httpContext, Func<Stream, Encoding, TextWriter> writerFactory, Type objectType, object @object)
         {
             if (httpContext == null)
             {
                 throw new ArgumentNullException(nameof(httpContext));
             }
 
+            if (writerFactory == null)
+            {
+                throw new ArgumentNullException(nameof(writerFactory));
+            }
+
             HttpContext = httpContext;
+            WriterFactory = writerFactory;
             ObjectType = objectType;
             Object = @object;
         }
@@ -33,5 +42,10 @@ namespace Microsoft.AspNet.Mvc.Formatters
         /// Gets or sets the <see cref="HttpContext"/> context associated with the current operation.
         /// </summary>
         public virtual HttpContext HttpContext { get; protected set; }
+
+        /// <summary>
+        /// Gets or sets a delegate used to create a <see cref="TextWriter"/> for writing the response.
+        /// </summary>
+        public virtual Func<Stream, Encoding, TextWriter> WriterFactory { get; protected set; }
     }
 }

src/Microsoft.AspNet.Mvc.Core/Infrastructure/ObjectResultExecutor.cs

@@ -3,7 +3,9 @@
 
 using System;
 using System.Collections.Generic;
+using System.IO;
 using System.Linq;
+using System.Text;
 using System.Threading.Tasks;
 using Microsoft.AspNet.Http;
 using Microsoft.AspNet.Mvc.Core;
@@ -32,6 +34,7 @@ namespace Microsoft.AspNet.Mvc.Infrastructure
         public ObjectResultExecutor(
             IOptions<MvcOptions> options,
             IActionBindingContextAccessor bindingContextAccessor,
+            IHttpResponseStreamWriterFactory writerFactory,
             ILoggerFactory loggerFactory)
         {
             if (options == null)
@@ -54,6 +57,7 @@ namespace Microsoft.AspNet.Mvc.Infrastructure
             OptionsFormatters = options.Value.OutputFormatters;
             RespectBrowserAcceptHeader = options.Value.RespectBrowserAcceptHeader;
             Logger = loggerFactory.CreateLogger<ObjectResultExecutor>();
+            WriterFactory = writerFactory.CreateWriter;
         }
 
         /// <summary>
@@ -76,6 +80,11 @@ namespace Microsoft.AspNet.Mvc.Infrastructure
         /// </summary>
         protected bool RespectBrowserAcceptHeader { get; }
 
+        /// <summary>
+        /// Gets the writer factory delegate.
+        /// </summary>
+        protected Func<Stream, Encoding, TextWriter> WriterFactory { get; }
+
         /// <summary>
         /// Executes the <see cref="ObjectResult"/>.
         /// </summary>
@@ -110,7 +119,12 @@ namespace Microsoft.AspNet.Mvc.Infrastructure
                 objectType = result.Value?.GetType();
             };
 
-            var formatterContext = new OutputFormatterWriteContext(context.HttpContext, objectType, result.Value);
+            var formatterContext = new OutputFormatterWriteContext(
+                context.HttpContext,
+                WriterFactory,
+                objectType,
+                result.Value);
+            
             var selectedFormatter = SelectFormatter(formatterContext, result.ContentTypes, formatters);
             if (selectedFormatter == null)
             {

src/Microsoft.AspNet.Mvc.Formatters.Json/JsonOutputFormatter.cs

@@ -108,7 +108,7 @@ namespace Microsoft.AspNet.Mvc.Formatters
             var response = context.HttpContext.Response;
             var selectedEncoding = context.ContentType?.Encoding ?? Encoding.UTF8;
 
-            using (var writer = new HttpResponseStreamWriter(response.Body, selectedEncoding))
+            using (var writer = context.WriterFactory(response.Body, selectedEncoding))
             {
                 WriteObject(writer, context.Object);
             }

src/Microsoft.AspNet.Mvc.Formatters.Xml/XmlDataContractSerializerOutputFormatter.cs

@@ -148,17 +148,23 @@ namespace Microsoft.AspNet.Mvc.Formatters
         }
 
         /// <summary>
-        /// Creates a new instance of <see cref="XmlWriter"/> using the given stream and the <see cref="WriterSettings"/>.
+        /// Creates a new instance of <see cref="XmlWriter"/> using the given <see cref="TextWriter"/> and
+        /// <see cref="XmlWriterSettings"/>.
         /// </summary>
-        /// <param name="writeStream">The stream on which the XmlWriter should operate on.</param>
+        /// <param name="writer">
+        /// The underlying <see cref="TextWriter"/> which the <see cref="XmlWriter"/> should write to.
+        /// </param>
+        /// <param name="xmlWriterSettings">
+        /// The <see cref="XmlWriterSettings"/>.
+        /// </param>
         /// <returns>A new instance of <see cref="XmlWriter"/></returns>
         public virtual XmlWriter CreateXmlWriter(
-            Stream writeStream,
+            TextWriter writer,
             XmlWriterSettings xmlWriterSettings)
         {
-            if (writeStream == null)
+            if (writer == null)
             {
-                throw new ArgumentNullException(nameof(writeStream));
+                throw new ArgumentNullException(nameof(writer));
             }
 
             if (xmlWriterSettings == null)
@@ -166,9 +172,10 @@ namespace Microsoft.AspNet.Mvc.Formatters
                 throw new ArgumentNullException(nameof(xmlWriterSettings));
             }
 
-            return XmlWriter.Create(
+            // We always close the TextWriter, so the XmlWriter shouldn't.
-                new HttpResponseStreamWriter(writeStream, xmlWriterSettings.Encoding),
+            xmlWriterSettings.CloseOutput = false;
-                xmlWriterSettings);
+
+            return XmlWriter.Create(writer, xmlWriterSettings);
         }
 
         /// <inheritdoc />
@@ -182,24 +189,26 @@ namespace Microsoft.AspNet.Mvc.Formatters
             var writerSettings = WriterSettings.Clone();
             writerSettings.Encoding = context.ContentType?.Encoding ?? Encoding.UTF8;
 
+            // Wrap the object only if there is a wrapping type.
             var value = context.Object;
-
+            var wrappingType = GetSerializableType(context.ObjectType);
-            using (var xmlWriter = CreateXmlWriter(context.HttpContext.Response.Body, writerSettings))
+            if (wrappingType != null && wrappingType != context.ObjectType)
             {
-                var wrappingType = GetSerializableType(context.ObjectType);
+                var wrapperProvider = WrapperProviderFactories.GetWrapperProvider(new WrapperProviderContext(
+                    declaredType: context.ObjectType,
+                    isSerialization: true));
 
-                // Wrap the object only if there is a wrapping type.
+                value = wrapperProvider.Wrap(value);
-                if (wrappingType != null && wrappingType != context.ObjectType)
+            }
+
+            var dataContractSerializer = GetCachedSerializer(wrappingType);
+
+            using (var textWriter = context.WriterFactory(context.HttpContext.Response.Body, writerSettings.Encoding))
+            {
+                using (var xmlWriter = CreateXmlWriter(textWriter, writerSettings))
                 {
-                    var wrapperProvider = WrapperProviderFactories.GetWrapperProvider(new WrapperProviderContext(
+                    dataContractSerializer.WriteObject(xmlWriter, value);
-                        declaredType: context.ObjectType,
-                        isSerialization: true));
-
-                    value = wrapperProvider.Wrap(value);
                 }
-
-                var dataContractSerializer = GetCachedSerializer(wrappingType);
-                dataContractSerializer.WriteObject(xmlWriter, value);
             }
 
             return TaskCache.CompletedTask;

src/Microsoft.AspNet.Mvc.Formatters.Xml/XmlSerializerOutputFormatter.cs

@@ -123,17 +123,23 @@ namespace Microsoft.AspNet.Mvc.Formatters
         }
 
         /// <summary>
-        /// Creates a new instance of <see cref="XmlWriter"/> using the given stream and the <see cref="WriterSettings"/>.
+        /// Creates a new instance of <see cref="XmlWriter"/> using the given <see cref="TextWriter"/> and
+        /// <see cref="XmlWriterSettings"/>.
         /// </summary>
-        /// <param name="writeStream">The stream on which the XmlWriter should operate on.</param>
+        /// <param name="writer">
+        /// The underlying <see cref="TextWriter"/> which the <see cref="XmlWriter"/> should write to.
+        /// </param>
+        /// <param name="xmlWriterSettings">
+        /// The <see cref="XmlWriterSettings"/>.
+        /// </param>
         /// <returns>A new instance of <see cref="XmlWriter"/></returns>
         public virtual XmlWriter CreateXmlWriter(
-            Stream writeStream,
+            TextWriter writer,
             XmlWriterSettings xmlWriterSettings)
         {
-            if (writeStream == null)
+            if (writer == null)
             {
-                throw new ArgumentNullException(nameof(writeStream));
+                throw new ArgumentNullException(nameof(writer));
             }
 
             if (xmlWriterSettings == null)
@@ -141,9 +147,10 @@ namespace Microsoft.AspNet.Mvc.Formatters
                 throw new ArgumentNullException(nameof(xmlWriterSettings));
             }
 
-            return XmlWriter.Create(
+            // We always close the TextWriter, so the XmlWriter shouldn't.
-                new HttpResponseStreamWriter(writeStream, xmlWriterSettings.Encoding),
+            xmlWriterSettings.CloseOutput = false;
-                xmlWriterSettings);
+
+            return XmlWriter.Create(writer, xmlWriterSettings);
         }
 
         /// <inheritdoc />
@@ -159,24 +166,26 @@ namespace Microsoft.AspNet.Mvc.Formatters
             var writerSettings = WriterSettings.Clone();
             writerSettings.Encoding = context.ContentType.Encoding ?? Encoding.UTF8;
 
+            // Wrap the object only if there is a wrapping type.
             var value = context.Object;
-
+            var wrappingType = GetSerializableType(context.ObjectType);
-            using (var xmlWriter = CreateXmlWriter(context.HttpContext.Response.Body, writerSettings))
+            if (wrappingType != null && wrappingType != context.ObjectType)
             {
-                var wrappingType = GetSerializableType(context.ObjectType);
+                var wrapperProvider = WrapperProviderFactories.GetWrapperProvider(new WrapperProviderContext(
+                    declaredType: context.ObjectType,
+                    isSerialization: true));
 
-                // Wrap the object only if there is a wrapping type.
+                value = wrapperProvider.Wrap(value);
-                if (wrappingType != null && wrappingType != context.ObjectType)
+            }
+
+            var xmlSerializer = GetCachedSerializer(wrappingType);
+
+            using (var textWriter = context.WriterFactory(context.HttpContext.Response.Body, writerSettings.Encoding))
+            {
+                using (var xmlWriter = CreateXmlWriter(textWriter, writerSettings))
                 {
-                    var wrapperProvider = WrapperProviderFactories.GetWrapperProvider(new WrapperProviderContext(
+                    xmlSerializer.Serialize(xmlWriter, value);
-                        declaredType: context.ObjectType,
-                        isSerialization: true));
-
-                    value = wrapperProvider.Wrap(value);
                 }
-
-                var xmlSerializer = GetCachedSerializer(wrappingType);
-                xmlSerializer.Serialize(xmlWriter, value);
             }
 
             return TaskCache.CompletedTask;

test/Microsoft.AspNet.Mvc.Core.Test/CreatedAtActionResultTests.cs

@@ -98,6 +98,7 @@ namespace Microsoft.AspNet.Mvc
             services.AddInstance(new ObjectResultExecutor(
                 options,
                 new ActionBindingContextAccessor(),
+                new TestHttpResponseStreamWriterFactory(),
                 NullLoggerFactory.Instance));
 
             return services.BuildServiceProvider();

test/Microsoft.AspNet.Mvc.Core.Test/CreatedAtRouteResultTests.cs

@@ -112,6 +112,7 @@ namespace Microsoft.AspNet.Mvc
             services.AddInstance(new ObjectResultExecutor(
                 options,
                 new ActionBindingContextAccessor(),
+                new TestHttpResponseStreamWriterFactory(),
                 NullLoggerFactory.Instance));
 
             return services.BuildServiceProvider();

test/Microsoft.AspNet.Mvc.Core.Test/CreatedResultTests.cs

@@ -99,6 +99,7 @@ namespace Microsoft.AspNet.Mvc
             services.AddInstance(new ObjectResultExecutor(
                 options,
                 new ActionBindingContextAccessor(),
+                new TestHttpResponseStreamWriterFactory(),
                 NullLoggerFactory.Instance));
 
             return services.BuildServiceProvider();

test/Microsoft.AspNet.Mvc.Core.Test/Formatters/HttpNotAcceptableOutputFormatterTest.cs

@@ -18,7 +18,11 @@ namespace Microsoft.AspNet.Mvc.Formatters
             // Arrange
             var formatter = new HttpNotAcceptableOutputFormatter();
 
-            var context = new OutputFormatterWriteContext(new DefaultHttpContext(), objectType: null, @object: null)
+            var context = new OutputFormatterWriteContext(
+                new DefaultHttpContext(),
+                new TestHttpResponseStreamWriterFactory().CreateWriter,
+                objectType: null,
+                @object: null)
             {
                 FailedContentNegotiation = failedContentNegotiation,
             };
@@ -36,7 +40,11 @@ namespace Microsoft.AspNet.Mvc.Formatters
             // Arrange
             var formatter = new HttpNotAcceptableOutputFormatter();
 
-            var context = new OutputFormatterWriteContext(new DefaultHttpContext(), objectType: null, @object: null)
+            var context = new OutputFormatterWriteContext(
+                new DefaultHttpContext(),
+                new TestHttpResponseStreamWriterFactory().CreateWriter,
+                objectType: null,
+                @object: null)
             {
                 FailedContentNegotiation = true,
             };
@@ -54,7 +62,11 @@ namespace Microsoft.AspNet.Mvc.Formatters
             // Arrange
             var formatter = new HttpNotAcceptableOutputFormatter();
 
-            var context = new OutputFormatterWriteContext(new DefaultHttpContext(), objectType: null, @object: null);
+            var context = new OutputFormatterWriteContext(
+                new DefaultHttpContext(),
+                new TestHttpResponseStreamWriterFactory().CreateWriter,
+                objectType: null,
+                @object: null);
 
             // Act
              await formatter.WriteAsync(context);

test/Microsoft.AspNet.Mvc.Core.Test/Formatters/NoContentFormatterTests.cs

@@ -43,7 +43,11 @@ namespace Microsoft.AspNet.Mvc.Formatters
             var type = declaredTypeAsString ? typeof(string) : typeof(object);
             var contentType = useNonNullContentType ? MediaTypeHeaderValue.Parse("text/plain") : null;
 
-            var context = new OutputFormatterWriteContext(new DefaultHttpContext(), type, value)
+            var context = new OutputFormatterWriteContext(
+                new DefaultHttpContext(),
+                new TestHttpResponseStreamWriterFactory().CreateWriter,
+                type,
+                value)
             {
                 ContentType = contentType,
             };
@@ -65,6 +69,7 @@ namespace Microsoft.AspNet.Mvc.Formatters
             // Arrange
             var context = new OutputFormatterWriteContext(
                 new DefaultHttpContext(),
+                new TestHttpResponseStreamWriterFactory().CreateWriter,
                 declaredType,
                 "Something non null.")
             {
@@ -92,6 +97,7 @@ namespace Microsoft.AspNet.Mvc.Formatters
             // Arrange
             var context = new OutputFormatterWriteContext(
                 new DefaultHttpContext(),
+                new TestHttpResponseStreamWriterFactory().CreateWriter,
                 typeof(string),
                 value)
             {
@@ -114,7 +120,11 @@ namespace Microsoft.AspNet.Mvc.Formatters
         public async Task WriteAsync_WritesTheStatusCode204()
         {
             // Arrange
-            var context = new OutputFormatterWriteContext(new DefaultHttpContext(), typeof(string), @object: null);
+            var context = new OutputFormatterWriteContext(
+                new DefaultHttpContext(),
+                new TestHttpResponseStreamWriterFactory().CreateWriter,
+                typeof(string),
+                @object: null);
 
             var formatter = new HttpNoContentOutputFormatter();
 
@@ -132,7 +142,11 @@ namespace Microsoft.AspNet.Mvc.Formatters
             var httpContext = new DefaultHttpContext();
             httpContext.Response.StatusCode = StatusCodes.Status201Created;
 
-            var context = new OutputFormatterWriteContext(httpContext, typeof(string), @object: null);
+            var context = new OutputFormatterWriteContext(
+                httpContext,
+                new TestHttpResponseStreamWriterFactory().CreateWriter,
+                typeof(string),
+                @object: null);
 
             var formatter = new HttpNoContentOutputFormatter();
 

test/Microsoft.AspNet.Mvc.Core.Test/Formatters/OutputFormatterTests.cs

@@ -53,7 +53,11 @@ namespace Microsoft.AspNet.Mvc.Formatters
                 formatter.SupportedEncodings.Add(Encoding.GetEncoding(supportedEncoding));
             }
 
-            var context = new OutputFormatterWriteContext(httpContext.Object, typeof(string), "someValue")
+            var context = new OutputFormatterWriteContext(
+                httpContext.Object,
+                new TestHttpResponseStreamWriterFactory().CreateWriter,
+                typeof(string),
+                "someValue")
             {
                 ContentType = MediaTypeHeaderValue.Parse(httpRequest.Headers[HeaderNames.Accept]),
             };
@@ -77,7 +81,11 @@ namespace Microsoft.AspNet.Mvc.Formatters
             formatter.SupportedMediaTypes.Clear();
             formatter.SupportedMediaTypes.Add(testContentType);
 
-            var context = new OutputFormatterWriteContext(new DefaultHttpContext(), objectType: null, @object: null)
+            var context = new OutputFormatterWriteContext(
+                new DefaultHttpContext(),
+                new TestHttpResponseStreamWriterFactory().CreateWriter,
+                objectType: null,
+                @object: null)
             {
                 ContentType = testContentType,
             };
@@ -102,7 +110,11 @@ namespace Microsoft.AspNet.Mvc.Formatters
             var mediaType = new MediaTypeHeaderValue("image/png");
             formatter.SupportedMediaTypes.Add(mediaType);
 
-            var context = new OutputFormatterWriteContext(new DefaultHttpContext(), objectType: null, @object: null);
+            var context = new OutputFormatterWriteContext(
+                new DefaultHttpContext(),
+                new TestHttpResponseStreamWriterFactory().CreateWriter,
+                objectType: null,
+                @object: null);
 
             // Act
             await formatter.WriteAsync(context);
@@ -117,7 +129,12 @@ namespace Microsoft.AspNet.Mvc.Formatters
         public void CanWriteResult_ForNullContentType_UsesFirstEntryInSupportedContentTypes()
         {
             // Arrange
-            var context = new OutputFormatterWriteContext(new DefaultHttpContext(), objectType: null, @object: null);
+            var context = new OutputFormatterWriteContext(
+                new DefaultHttpContext(),
+                new TestHttpResponseStreamWriterFactory().CreateWriter,
+                objectType: null,
+                @object: null);
+
             var formatter = new TestOutputFormatter();
 
             // Act
@@ -151,7 +168,11 @@ namespace Microsoft.AspNet.Mvc.Formatters
             formatter.SupportedMediaTypes.Add(MediaTypeHeaderValue.Parse("application/json"));
             formatter.SupportedTypes.Add(typeof(int));
 
-            var context = new OutputFormatterWriteContext(new DefaultHttpContext(),typeof(string), "Hello, world!")
+            var context = new OutputFormatterWriteContext(
+                new DefaultHttpContext(),
+                new TestHttpResponseStreamWriterFactory().CreateWriter,
+                typeof(string),
+                "Hello, world!")
             {
                 ContentType = formatter.SupportedMediaTypes[0],
             };

test/Microsoft.AspNet.Mvc.Core.Test/Formatters/StreamOutputFormatterTest.cs

@@ -23,7 +23,11 @@ namespace Microsoft.AspNet.Mvc.Formatters
             var formatter = new StreamOutputFormatter();
             var contentTypeHeader = contentType == null ? null : new MediaTypeHeaderValue(contentType);
 
-            var context = new OutputFormatterWriteContext(new DefaultHttpContext(), type, new MemoryStream())
+            var context = new OutputFormatterWriteContext(
+                new DefaultHttpContext(),
+                new TestHttpResponseStreamWriterFactory().CreateWriter,
+                type,
+                new MemoryStream())
             {
                 ContentType = contentTypeHeader,
             };
@@ -44,7 +48,11 @@ namespace Microsoft.AspNet.Mvc.Formatters
             var formatter = new StreamOutputFormatter();
             var contentTypeHeader = contentType == null ? null : new MediaTypeHeaderValue(contentType);
 
-            var context = new OutputFormatterWriteContext(new DefaultHttpContext(), type, new SimplePOCO())
+            var context = new OutputFormatterWriteContext(
+                new DefaultHttpContext(),
+                new TestHttpResponseStreamWriterFactory().CreateWriter,
+                type,
+                new SimplePOCO())
             {
                 ContentType = contentTypeHeader,
             };
@@ -66,7 +74,11 @@ namespace Microsoft.AspNet.Mvc.Formatters
             var formatter = new StreamOutputFormatter();
             var @object = type != null ? Activator.CreateInstance(type) : null;
 
-            var context = new OutputFormatterWriteContext(new DefaultHttpContext(), type, @object);
+            var context = new OutputFormatterWriteContext(
+                new DefaultHttpContext(),
+                new TestHttpResponseStreamWriterFactory().CreateWriter,
+                type,
+                @object);
 
             // Act
             var result = formatter.CanWriteResult(context);
@@ -90,7 +102,11 @@ namespace Microsoft.AspNet.Mvc.Formatters
             var bufferingFeature = new TestBufferingFeature();
             httpContext.Features.Set<IHttpBufferingFeature>(bufferingFeature);
 
-            var context = new OutputFormatterWriteContext(httpContext, typeof(Stream), new MemoryStream(expected));
+            var context = new OutputFormatterWriteContext(
+                httpContext,
+                new TestHttpResponseStreamWriterFactory().CreateWriter,
+                typeof(Stream),
+                new MemoryStream(expected));
 
             // Act
             await formatter.WriteAsync(context);

test/Microsoft.AspNet.Mvc.Core.Test/Formatters/StringOutputFormatterTests.cs

@@ -42,7 +42,11 @@ namespace Microsoft.AspNet.Mvc.Formatters
             var formatter = new StringOutputFormatter();
             var type = useDeclaredTypeAsString ? typeof(string) : typeof(object);
 
-            var context = new OutputFormatterWriteContext(new DefaultHttpContext(), type, value);
+            var context = new OutputFormatterWriteContext(
+                new DefaultHttpContext(),
+                new TestHttpResponseStreamWriterFactory().CreateWriter,
+                type,
+                value);
             context.ContentType = MediaTypeHeaderValue.Parse("application/json");
 
             // Act
@@ -66,7 +70,11 @@ namespace Microsoft.AspNet.Mvc.Formatters
             httpContext.Setup(o => o.Response).Returns(response.Object);
 
             var formatter = new StringOutputFormatter();
-            var context = new OutputFormatterWriteContext(httpContext.Object, typeof(string), @object: null);
+            var context = new OutputFormatterWriteContext(
+                httpContext.Object,
+                new TestHttpResponseStreamWriterFactory().CreateWriter,
+                typeof(string),
+                @object: null);
 
             // Act
             await formatter.WriteResponseBodyAsync(context);

test/Microsoft.AspNet.Mvc.Core.Test/HttpNotFoundObjectResultTest.cs

@@ -75,6 +75,7 @@ namespace Microsoft.AspNet.Mvc
             services.AddInstance(new ObjectResultExecutor(
                 options,
                 new ActionBindingContextAccessor(),
+                new TestHttpResponseStreamWriterFactory(),
                 NullLoggerFactory.Instance));
 
             return services.BuildServiceProvider();

test/Microsoft.AspNet.Mvc.Core.Test/HttpOkObjectResultTest.cs

@@ -79,6 +79,7 @@ namespace Microsoft.AspNet.Mvc
             services.AddInstance(new ObjectResultExecutor(
                 options,
                 new ActionBindingContextAccessor(),
+                new TestHttpResponseStreamWriterFactory(),
                 NullLoggerFactory.Instance));
 
             return services.BuildServiceProvider();

test/Microsoft.AspNet.Mvc.Core.Test/Infrastructure/ObjectResultExecutorTest.cs

@@ -32,7 +32,12 @@ namespace Microsoft.AspNet.Mvc.Infrastructure
                 new TestJsonOutputFormatter(), // This will be chosen based on the accept header
             };
 
-            var context = new OutputFormatterWriteContext(new DefaultHttpContext(), objectType: null, @object: null);
+            var context = new OutputFormatterWriteContext(
+                new DefaultHttpContext(),
+                new TestHttpResponseStreamWriterFactory().CreateWriter,
+                objectType: null,
+                @object: null);
+
             context.HttpContext.Request.Headers[HeaderNames.Accept] = "application/json";
 
             // Act
@@ -58,7 +63,12 @@ namespace Microsoft.AspNet.Mvc.Infrastructure
                 new TestJsonOutputFormatter(), // This will be chosen based on the content type
             };
 
-            var context = new OutputFormatterWriteContext(new DefaultHttpContext(), objectType: null, @object: null);
+            var context = new OutputFormatterWriteContext(
+                new DefaultHttpContext(),
+                new TestHttpResponseStreamWriterFactory().CreateWriter,
+                objectType: null,
+                @object: null);
+
             context.HttpContext.Request.Headers[HeaderNames.Accept] = "application/xml"; // This will not be used
 
             // Act
@@ -83,7 +93,12 @@ namespace Microsoft.AspNet.Mvc.Infrastructure
                 new TestXmlOutputFormatter(),
             };
 
-            var context = new OutputFormatterWriteContext(new DefaultHttpContext(), objectType: null, @object: null);
+            var context = new OutputFormatterWriteContext(
+                new DefaultHttpContext(),
+                new TestHttpResponseStreamWriterFactory().CreateWriter,
+                objectType: null,
+                @object: null);
+
             context.HttpContext.Request.Headers[HeaderNames.Accept] = "application/xml"; // This will not be used
 
             // Act
@@ -150,7 +165,12 @@ namespace Microsoft.AspNet.Mvc.Infrastructure
                 new TestJsonOutputFormatter(),
             };
 
-            var context = new OutputFormatterWriteContext(new DefaultHttpContext(), objectType: null, @object: null);
+            var context = new OutputFormatterWriteContext(
+                new DefaultHttpContext(),
+                new TestHttpResponseStreamWriterFactory().CreateWriter,
+                objectType: null,
+                @object: null);
+
             context.HttpContext.Request.Headers[HeaderNames.Accept] = acceptHeader;
 
             // Act
@@ -177,7 +197,11 @@ namespace Microsoft.AspNet.Mvc.Infrastructure
                 new TestXmlOutputFormatter(),
             };
 
-            var context = new OutputFormatterWriteContext(new DefaultHttpContext(), objectType: null, @object: null);
+            var context = new OutputFormatterWriteContext(
+                new DefaultHttpContext(),
+                new TestHttpResponseStreamWriterFactory().CreateWriter,
+                objectType: null,
+                @object: null);
 
             // Act
             var formatter = executor.SelectFormatter(
@@ -203,7 +227,12 @@ namespace Microsoft.AspNet.Mvc.Infrastructure
                 new TestJsonOutputFormatter(),
             };
 
-            var context = new OutputFormatterWriteContext(new DefaultHttpContext(), objectType: null, @object: null);
+            var context = new OutputFormatterWriteContext(
+                new DefaultHttpContext(),
+                new TestHttpResponseStreamWriterFactory().CreateWriter, 
+                objectType: null,
+                @object: null);
+
             context.HttpContext.Request.Headers[HeaderNames.Accept] = "text/custom, application/custom";
 
             // Act
@@ -434,6 +463,7 @@ namespace Microsoft.AspNet.Mvc.Infrastructure
             return new TestObjectResultExecutor(
                 options ?? new TestOptionsManager<MvcOptions>(),
                 bindingContextAccessor,
+                new TestHttpResponseStreamWriterFactory(),
                 NullLoggerFactory.Instance);
         }
 
@@ -486,9 +516,10 @@ namespace Microsoft.AspNet.Mvc.Infrastructure
         {
             public TestObjectResultExecutor(
                 IOptions<MvcOptions> options, 
-                IActionBindingContextAccessor bindingContextAccessor, 
+                IActionBindingContextAccessor bindingContextAccessor,
+                IHttpResponseStreamWriterFactory writerFactory,
                 ILoggerFactory loggerFactory) 
-                : base(options, bindingContextAccessor, loggerFactory)
+                : base(options, bindingContextAccessor, writerFactory, loggerFactory)
             {
             }
 

test/Microsoft.AspNet.Mvc.Core.Test/ObjectResultTests.cs

@@ -68,6 +68,7 @@ namespace Microsoft.AspNet.Mvc
             services.AddInstance(new ObjectResultExecutor(
                 new TestOptionsManager<MvcOptions>(),
                 new ActionBindingContextAccessor(),
+                new TestHttpResponseStreamWriterFactory(),
                 NullLoggerFactory.Instance));
             services.AddInstance<ILoggerFactory>(NullLoggerFactory.Instance);
 

test/Microsoft.AspNet.Mvc.Formatters.Json.Test/JsonOutputFormatterTests.cs

@@ -175,6 +175,7 @@ namespace Microsoft.AspNet.Mvc.Formatters
 
             var outputFormatterContext = new OutputFormatterWriteContext(
                 actionContext.HttpContext,
+                new TestHttpResponseStreamWriterFactory().CreateWriter,
                 typeof(string),
                 content)
             {
@@ -218,7 +219,11 @@ namespace Microsoft.AspNet.Mvc.Formatters
             var mediaTypeHeaderValue = MediaTypeHeaderValue.Parse(contentType);
 
             var actionContext = GetActionContext(mediaTypeHeaderValue, responseStream);
-            return new OutputFormatterWriteContext(actionContext.HttpContext, outputType, outputValue)
+            return new OutputFormatterWriteContext(
+                actionContext.HttpContext,
+                new TestHttpResponseStreamWriterFactory().CreateWriter,
+                outputType,
+                outputValue)
             {
                 ContentType = mediaTypeHeaderValue,
             };

test/Microsoft.AspNet.Mvc.Formatters.Xml.Test/XmlDataContractSerializerOutputFormatterTest.cs

@@ -599,7 +599,11 @@ namespace Microsoft.AspNet.Mvc.Formatters.Xml
             Type outputType,
             string contentType = "application/xml; charset=utf-8")
         {
-            return new OutputFormatterWriteContext(GetHttpContext(contentType), outputType, outputValue);
+            return new OutputFormatterWriteContext(
+                GetHttpContext(contentType),
+                new TestHttpResponseStreamWriterFactory().CreateWriter,
+                outputType,
+                outputValue);
         }
 
         private static HttpContext GetHttpContext(string contentType)

test/Microsoft.AspNet.Mvc.Formatters.Xml.Test/XmlSerializerOutputFormatterTest.cs

@@ -360,7 +360,11 @@ namespace Microsoft.AspNet.Mvc.Formatters.Xml
             Type outputType,
             string contentType = "application/xml; charset=utf-8")
         {
-            return new OutputFormatterWriteContext(GetHttpContext(contentType), outputType, outputValue);
+            return new OutputFormatterWriteContext(
+                GetHttpContext(contentType),
+                new TestHttpResponseStreamWriterFactory().CreateWriter,
+                outputType,
+                outputValue);
         }
 
         private static HttpContext GetHttpContext(string contentType)

test/Microsoft.AspNet.Mvc.Formatters.Xml.Test/project.json

@@ -4,9 +4,11 @@
   },
   "dependencies": {
     "Microsoft.AspNet.Http": "1.0.0-*",
-    "Microsoft.AspNet.Mvc" : "6.0.0-*",
+    "Microsoft.AspNet.Mvc": "6.0.0-*",
     "Microsoft.AspNet.Mvc.Formatters.Xml" : "6.0.0-*",
+    "Microsoft.AspNet.Mvc.TestCommon": { "type": "build", "version": "6.0.0-*" },
     "Microsoft.AspNet.Testing": "1.0.0-*",
+    "Microsoft.Extensions.WebEncoders.Testing": "1.0.0-*",
     "Moq": "4.2.1312.1622",
     "xunit.runner.aspnet": "2.0.0-aspnet-*"
   },

test/Microsoft.AspNet.Mvc.WebApiCompatShimTest/BadRequestErrorMessageResultTest.cs

@@ -77,6 +77,7 @@ namespace System.Web.Http
             services.AddInstance(new ObjectResultExecutor(
                 options,
                 new ActionBindingContextAccessor(),
+                new TestHttpResponseStreamWriterFactory(),
                 NullLoggerFactory.Instance));
 
             return services.BuildServiceProvider();

test/Microsoft.AspNet.Mvc.WebApiCompatShimTest/ExceptionResultTest.cs

@@ -77,6 +77,7 @@ namespace System.Web.Http
             services.AddInstance(new ObjectResultExecutor(
                 options,
                 new ActionBindingContextAccessor(),
+                new TestHttpResponseStreamWriterFactory(),
                 NullLoggerFactory.Instance));
 
             return services.BuildServiceProvider();

test/Microsoft.AspNet.Mvc.WebApiCompatShimTest/HttpResponseMessageOutputFormatterTests.cs

@@ -151,7 +151,11 @@ namespace Microsoft.AspNet.Mvc.WebApiCompatShimTest
             Type outputType,
             HttpContext httpContext)
         {
-            return new OutputFormatterWriteContext(httpContext, outputType, outputValue);
+            return new OutputFormatterWriteContext(
+                httpContext,
+                new TestHttpResponseStreamWriterFactory().CreateWriter,
+                outputType,
+                outputValue);
         }
     }
 }

test/Microsoft.AspNet.Mvc.WebApiCompatShimTest/InvalidModelStateResultTest.cs

@@ -90,6 +90,7 @@ namespace System.Web.Http
             services.AddInstance(new ObjectResultExecutor(
                 options,
                 new ActionBindingContextAccessor(),
+                new TestHttpResponseStreamWriterFactory(),
                 NullLoggerFactory.Instance));
 
             return services.BuildServiceProvider();

test/Microsoft.AspNet.Mvc.WebApiCompatShimTest/NegotiatedContentResultTest.cs

@@ -77,6 +77,7 @@ namespace System.Web.Http
             services.AddInstance(new ObjectResultExecutor(
                 options,
                 new ActionBindingContextAccessor(),
+                new TestHttpResponseStreamWriterFactory(),
                 NullLoggerFactory.Instance));
 
             return services.BuildServiceProvider();

test/Microsoft.AspNet.Mvc.WebApiCompatShimTest/TestHttpResponseStreamWriterFactory.cs

@@ -0,0 +1,17 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System.IO;
+using System.Text;
+using Microsoft.AspNet.Mvc.Infrastructure;
+
+namespace Microsoft.AspNet.Mvc
+{
+    public class TestHttpResponseStreamWriterFactory : IHttpResponseStreamWriterFactory
+    {
+        public TextWriter CreateWriter(Stream stream, Encoding encoding)
+        {
+            return new HttpResponseStreamWriter(stream, encoding);
+        }
+    }
+}